Improvement in spectacles



. G. D. BDMONSON. SPECTACLES.

No. 65,800x PatentedJune 18, 1867.

@eine iftatesv atwt @fitte GEORGE D. EDMONDSON,4 OF DETROIT, MICHIGAN, ASSIGNOR TO HIM- SELF AND ALBERT R. CLARK, OF'SAME PLAGE.

Lettere Patent No. 65,800, datcdvJuvne I8, 1867.

' IMPROVEMENT 1N. errements.

TO WHOM IT MAY CONCERN:

Bc it known that I, GEORGE D. EDMo-NDSON, of Detroit, in the county of Wayne, and State of Michigan,

have invented certain new and useful Improvements in Spectacles; and I do hereby declare the following to be a full, clear, and exact description of the nature, construction, and operation of the same, suiliei'ent to enable others skilled in the art to which my invention appertains to make and use the same, reference being had to the accompanying drawings, which are made part ofithis specification, and in which- Figure 1 is a vperspective view..

Figure 2 is a section on the-line we', fig. 1.

Each lens consists of two pieces, of different magnifying powers, and set iu different planes. The line of division between the two is the horizontal mid-section; the upper portion `ispf greater focal distance for viewing more distant objects, f The plane of the upper portion is at right angles to that of the bows, and at about the same angle to the axis of the eyes when adjusted horizontally; The plane of the lower halves is inclined to the former so as to b e about at right angles to the axis of the eyes when declined in reading, Ete.

In the drawingmAA are the bezels', which conne the lenses; B the bows, by which the spectacles are clasped to thc head; and C lthe bridge by which they are supported iuposition. The lenses in each case consist of two pieces. The npper half, I), is of a longer focal distance than the'other, that is, less convex; it is designed for distant objects such as ordinarily seen by a partyiwalking, objects which are assumed to be about the height of the eye and short distances above and below. The lower half, E, is of a more convex character, so as to suit the eye for reading, writing, needlework, Ate., for which purpose a stronger power is generally required, as is familiarly instanced'in the case of a person reading with spectacles and looking over them at persons or other ordinary objects at a greater distance than the book. Itis desired to maintain the proper relative positions of thc two portions to the axis of the eyes, and to secure this the upperhalf is in a plane at right angles to the bows B, so that 'the portion D meets the requirements of the eye when looking straight forward at the scene, and the portion E is at such an angle with the portion Das 'will correspond to the ordinary declination of the axis of the eyes in reading, Ste. This adjustment of focal length and nlanc to the varying conditions and requirements is avaluable and hitherto undeveloped fea-taire in spectacles.

I Vhave heretofore spoken of the invention in reference to the use oi' convex glasses, in which case the upper portion has the least power, but my improvement is also adapted for glasses for those troubled with myopie, in which case the upper half would he the stronger power, more concave thanthe lower.

I-Iaving described my invention, what I- claim therein as new, and desire to secure by Letters Patent, is The spectacles with lenses, each of which consists of -two pieces of different relative convexity, and set at a diierent angle in the bezel, substantially as described. v

GEORGE D. EDMONDSON.

Witnesses:

DANL JACKSON, O. P. Hmm. 

